Gold-annealing apparatus.



PATENTED APR. 7, 1903.

0. 1 DWIGHT. GOLD ANNEALING APPARATUS.

APPLICATION FILED JULY 31, 1902.

H0 MODEL.

1 11 IIEIIJIII lrlllillliltlllflivi GAIIO rgzys A W n Mi Lyzgfar'ghysses UNITED STATES PATENT OFFICE.

CHARLES F. DWIGHT, OF MARCUS, IOWA.

GOLD-ANNEALING APPARATUS.

SPECIFICATION forming part of Letters Patent No. 724,826, dated April 7,1903.

Application filed July 31,1902. Serial No. 117,885. aromas.)

To all whom, itmcty concern: 7

Be it known that I, CHARLES F. DWIGHT, a citizen of the United States,residing at Marcus, in the county of Cherokee and State of Iowa, haveinvented a new and nsefulGold- Annealing Apparatus, of which thefollowing is a specification.

My invention relates to certain improvements in annealing apparatus, andhas for its principal object to provide an improvedform ot'annealing-oven intended principally for the use of dentists in annealinggold-and gold compositions for the filling of teeth.

A further object of the invention is to provide a form ofannealing-oven-in which the sheet of gold will be subjected topractically the same temperature on both sides, and thus anneal moreuniformly than is possible in the apparatus usually employed for thispurpose, where the gold is placed on a heated plate and its uppersurface exposed to the air.

With these and other objects in view the invention consists in the novelconstructionand combination of parts hereinafter described, illustrated.in the accompanying drawings, and particularly pointed out .in theappended claims.

In the drawings, Figure 1 is a longitudinal sectional elevation of anannealing apparatus embodying the invention. Fig. 2 is a plan View ofthe same with the lid or cover removed. Fig. 3 is a view similar toFig.1, illustrating a slightly-modified construction of annealing-oven.Fig. 4 is a central longitudinal sectional elevation of the same. Fig.-5 is a sectional elevation illustrating a further modification. r

Similar numerals ofreference are employed to indicatecorresponding'parts throughout the several figures of the drawings.

In the annealing of gold and gold compositions for dental purposes theusual practice consists in placing the'gold on a heated plate, with theupper surface of the sheet exposed to the atmosphere. The heat isunevenly distributed, and the gold is not annealed as perfectly as itshould be.

The presentinvention aims principallyto provide a device of a simple andinexpensive nature for use by dentists and in which both sides of thesheet will be subjected to approximately the same temperature and theannealing operation thus rendered more uniform.

InFigs. 1 and 2 of the drawings, 1 designates a semispherical shell,approximately bowl-shaped and provided with inner and outer walls 2 and3, respectively. The walls are formed of metal and maintained in spacedrelation by rivets or bolts 4, extending through and secured to bothwalls and surrounded between the walls by a spacing sleeve or collar 5.At the central portion of the outer wall 2 is a socket member 7, whichmay be connected to a burner or other device capable of supplyingsufficient heat for the annealing operation. In most cases this socketwould be so shaped as to be capable of attachment to the ordinary dentallamp. The upper portion or lid of the apparatus is of a shapesubstantially similar to the lower portion and comprises inner and outerwalls 9 and 10, held in spaced relation by any suitable means, as by acentral pin 13, provided with a ring'or knob l tfor'convenience inremoving the cover from the lower portion of the 'oven. The lower edgesof the cover portion are slightly flanged, as indicated at 15, in orderthat they may fit closely. on the upper edges of the walls 2 and 3',andthus form a continuous flue for the products of combustion around thecircular oven formed by the walls or casings 2 and 9. In the top of theouter section 10 of the cover is an outlet 16 for the products ofcombustion, and in the upper portion'ot both the inner and outersections are alinin g openings 17, covered with mica or some othertransparent material, through which the operator may observe theannealing process. In the upper portion of the lower or stationarysection of the oven is a mica plate 19, on which the gold is placed andthere subjected to heat from both sides.

The operator is enabled to observe the procedges of the inner and outerwalls are bent to form flanges 18, in which are sprung mica sheets 19and 20, the whole forming a continuous duct or fine for the passage ofthe products of combustion and giving the operator a clear view of thewhole of the interior of the oven. One end of the oven is closed by thestationary wall, and at the opposite end the outer metallic sheet 3 isflanged, as indicated at 21, to form a guide for the reception andsupport of a vertically-movable door or closure 22. In this oven thegold is supported on a suitable annealing-plate 19, which may bereadilyremoved, together with the gold, from position in the oven whenthe annealing operation is concluded.

Fig. 5 illustrates a still further embodiment of the invention. In thisconstruction the inner and outer casings and 26 are approximatelyrectangular in form and each is provided at one side with a door, thetwo doors 2 and 27 being firmly secured together and placed in positionand removed by means of a handle or knob 28.

In all cases the gold is maintained in the interior of an oven havingdouble walls, the latter serving as ducts or flues for the products ofcombustion and the gold being subjected to approximately the sametemperature on both surfaces.

While the construction herein described, and illustrated in theaccompanying drawings, is the preferred form of the device, it isobvious that various changes in the form, proportions, size, and minordetails of structure maybe made without departing from the spirit orsacrificing anyof the advantages of the invention.

Having thus described my invention, what I claim is 1.Adentalgold-annealer comprisinga sectional oven having an inner supportfor the gold to be annealed, each section being provided with doublewalls forming a flue, the tines registering with each other when thesections are assembled to form a continuous passage for heated gases orproducts of combustion.

2. Adentalgold-annealercomprisinganinclosed oven having a relativelystationary section provided with a double wall forming a. flue, and aremovable door or lid also having a flue to connect with that of thestationary section when in closed position.

3. A dental gold -annealer comprising a lower section having two spacedwalls to form a flue, means for holding the walls in spaced relation, asupport for the gold to be annealed, and a removable cover having innerand outer walls held in spaced relation and adapted to engage the edgesof the walls of the lower section to thereby form a continuousflue-space around the oven.

4. A dental gold annealer comprising a lower section having double wallsand provided with a socket for connection to a source of heat-supply,rivets or bolts connecting the double walls and surrounded by spacingsleeves or collars, a gold-supporting plate carried by the lowersection, a removable upper section having spaced inner and outer Wallsadapted to engage the walls of the lower section to form a continuousflue-space, the outer wall of the upper sectionhavinga vent orescape-flue and both walls of the upper section having alining openingscovered with transparent material. 4

In testimony that I claim the foregoing as my own I have hereto atfixedmy signature in the presence of two witnesses.

CHARLES F. DVVIGI'IT.

Witnesses:

JACOB ROHRER, G. H. STORM.

